Promising therapeutical properties of mitochondria-targeted antioxidants (MTAs) have been described (see, e.g., US2008176929; Skulachev et al. (2009), Biochim. Biophys. Acta, 1787:437-61). The experiments performed which revealed these properties were done with freshly prepared solutions of MTAs and made by dissolving of ethanol stock solutions preserved at −80° C. shortly before administration of the preparation to animals. Such method of preparation and administration is not suitable or realistic for preparation of pharmaceuticals as it is extremely inconvenient if not impossible for industrial manufacturing, logistics, and use by patients. Attempts to develop a pharmaceutical composition (for oral administration or injection) with acceptable stability revealed that MTAs are not stable in most types of oral or injectable compositions. Stable pharmaceutical composition containing MTAs possessing acceptable stability have not been described up to now. Accordingly, improved liquid formulations with stability are still needed.